Microsoft's Small Business Center says that widespread use of email on mobile devices has changed a few email etiquette rules and details seven tips for refining your mobile email manners. The article focuses on improving email you send to mobile recipients, like sticking to subject-line-only messages when possible and keeping emails brief. We've given you our top tips for improving your email etiquette on your desktop, but in the face of increasing mobile email, the way we communicate over email could use some tweaking. If you consider yourself a mobile email guru, let's hear your tips for proper mobile email etiquette in the comments.